NONE · BOEING 757-225 · 2007-10-28 · Charlotte, NC, USA
Event
NTSB number
ENG08IA001
Event ID
20081219X65251
Type
Incident
Date
2007-10-28
Location
Charlotte, NC, USA
Coordinates
35.208984, -80.952576
Injuries
Highest injury
NONE
Fatal
0
Serious
0
Minor
0
Uninjured
0
Total aboard
0
Aircraft
Make
BOEING
Model
757-225
Registration
N919UW
FAR Part
121
Engines
2
Damage
MINR
Conditions
Light
NR
Weather
Unk
Probable cause
The truck beam fracture initiated by fatigue and stress corrosion cracking from pits that were present on the ID surface of the truck beam, under the protective finishes. Crack propagation occurred by alternating modes of stress corrosion cracking and fatigue until final fracture occurred by ultimate ductile separation. The condition of the surface finishes and base metal at the fracture initiation area indicated that the pitting was present before the last application of cadmium plating and primer, rather than the result of corrosion since the last overhaul. The observed pitting appeared to be remnants of incomplete corrosion removal during the last overhaul.